media: videobuf2-v4l2: add vb2_request_queue/validate helpers

The generic vb2_request_validate helper function checks if
there are buffers in the request and if so, prepares (validates)
all objects in the request.

The generic vb2_request_queue helper function queues all buffer
objects in the validated request.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index 9c652afa62abc17d275a55e2a47a885a1e1ad059..364b1fea382684709627b6186dd1ddf46f862752 100644 (file)
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -1100,6 +1100,57 @@ void vb2_ops_wait_finish(struct vb2_queue *vq)
 }
 EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);
 
+/*
+ * Note that this function is called during validation time and
+ * thus the req_queue_mutex is held to ensure no request objects
+ * can be added or deleted while validating. So there is no need
+ * to protect the objects list.
+ */
+int vb2_request_validate(struct media_request *req)
+{
+       struct media_request_object *obj;
+       int ret = 0;
+
+       if (!vb2_request_has_buffers(req))
+               return -ENOENT;
+
+       list_for_each_entry(obj, &req->objects, list) {
+               if (!obj->ops->prepare)
+                       continue;
+
+               ret = obj->ops->prepare(obj);
+               if (ret)
+                       break;
+       }
+
+       if (ret) {
+               list_for_each_entry_continue_reverse(obj, &req->objects, list)
+                       if (obj->ops->unprepare)
+                               obj->ops->unprepare(obj);
+               return ret;
+       }
+       return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_request_validate);
+
+void vb2_request_queue(struct media_request *req)
+{
+       struct media_request_object *obj, *obj_safe;
+
+       /*
+        * Queue all objects. Note that buffer objects are at the end of the
+        * objects list, after all other object types. Once buffer objects
+        * are queued, the driver might delete them immediately (if the driver
+        * processes the buffer at once), so we have to use
+        * list_for_each_entry_safe() to handle the case where the object we
+        * queue is deleted.
+        */
+       list_for_each_entry_safe(obj, obj_safe, &req->objects, list)
+               if (obj->ops->queue)
+                       obj->ops->queue(obj);
+}
+EXPORT_SYMBOL_GPL(vb2_request_queue);
+
 MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
 MODULE_LICENSE("GPL");

diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h
index 91a2b3e1a642af6d2eb7a3c2c6eb6a8f23564153..727855463838c9e1773897ae66427a0226e09ede 100644 (file)
--- a/include/media/videobuf2-v4l2.h
+++ b/include/media/videobuf2-v4l2.h
@@ -303,4 +303,8 @@ void vb2_ops_wait_prepare(struct vb2_queue *vq);
  */
 void vb2_ops_wait_finish(struct vb2_queue *vq);
 
+struct media_request;
+int vb2_request_validate(struct media_request *req);
+void vb2_request_queue(struct media_request *req);
+
 #endif /* _MEDIA_VIDEOBUF2_V4L2_H */